Aerial mine



March 4, 1947; M. P. LAUGHLIN AERIAL MINE Filed June 10, 1940 4Sheets-Sheet l M t 1947- M. P. LAUGHLIN 2,416,877

AERIAL MINE Filed June 10, 1940 4 Sheets-Sheet 2 March 4, 1947. M. P.LAUGHLIN 2,416,877

AERIAL MINE Filed June 10, 1940 4 Sheets-Sheet 3 4, 1947. M. P. LAUGHLIN2,416,877

v AERIAL MINE Filed June 10, 1940 4 Sheets-Sheet 4 Patented Mar. 4, 1947UNITED STATES PATENT Price 8 Claims. 1

This invention relates to aerial mines and to a method of laying anddisposing the same.

Aerial mines of kite, balloon, and parachute type heretofore employedhave involved moorings and the like to assure their being in position ata given time in a given spot, and hence have of necessity been made solarge that they were not only expensive to prepare and maintain but wereeasily visible and avoided by the enemy with little trouble. Anotherdifiiculty with such devices has been that so large a proportion oftheir buoyancy was needed to support the mooring lines that but littleremained to support any explosive elements. Further, the erraticgyrations of a balloon on a mooring in a breeze of any force oftenplaced it far from its intended position when most needed to interceptenemy aircraft and the like.

It is the purpose of this present invention to provide a mine or grenadeof such small size and cost that it may be made and used in largequantities, of a type and constructed of parts adapted to quantityproduction by peacetime production machinery so that it will beavailable in any quantity required, to provide means for so laying suchminesthat their position at a given time can be accurately known, and toprovide means for automatically disposing of such mines after theirperiod of elfective use so that the danger from drifting and escapedmines may be eliminated.

The ultimate object of this invention is to provide means for accuratelylaunching and controlling free-fioating mines in such a fashion that thecourse of the free mines and of invading vessels will intercept and thepoint of such interception be accurately known.

The following description and the attached drawings will serve todisclose certain mechanism providing one embodiment of my invention anda preferred method of using the invention.

Fig. 1 is a view in partial cross-section of a preferred form of mine.

Figs. 2 and 3, also in partial cross-section, show parts of the firingmechanism of the mine of Fig. 1.

Fig. 4 is a fragmentary view of the trigger release mechanism.

Fig. 5 is a sectional view of the balloon inflating and deflatingmechanism.

Fig. 6 is an elevation in partial section of the laying and settingmechanism.

Fig. 7 is a view taken in the direction of the arrows from line 'I'| ofFig. 6.

Fig. 8 is a view taken in the direction of the 2 arrows from line 8-8 ofFig. 6, and is in partial section.

Fig. 9 serves to show the mine storage and feeding rack used as a partof my invention.

Fig. 10 is a diagrammatic view of the aerial mines in operation.

Fig. 11 is a cross-sectional view of a preferred form of container forthe mines and mine racks before use.

Fig. 12 is an elevation of part of the mechanism of Fig. 6.

Fig. 13 is a second view of the mechanism of Fig. 6 for the parts in asecond position,

Fig. 14 is an end View of the mine rack of Figs. 11, 12, and 13.

A type of aerial mine suited to the practice of my invention and forminga part thereof is illustrated in cross-section in Fig. 1, wherein Illsis the balloon shell of expansible type material such as rubber,rubberized cloth, or the like, provided with a neck or appendix H, whichforms the means of inflating the balloon, of supporting the explosivecharge, detonator and firing mechanism, and of transporting all of thisto the place of release. The method of manufacture of shell lfls, formsno part of this invention, and it may be made after any of the wellknown methods of manufacture, such as molding in a single piece orassembling in segments, and is preferably of spherical or pear-shapedform.

Within the appendix l I is arranged a detonator mechanism 20, comprisinga body 2|, over which fits a shell 48. Body 2| is provided with aninternal bore having an enlarged portion 22, opening into a reducedportion 23, which in turn opens into a bore 2 having an opening 25 inthe side thereof, and openin in turn into a reduced bore 26, extendingto the end of body 2| at the nipple 21, adjacent to which is provided aflange 28, whose purposes will be described.

The bore portion 22 serves to permit the introduetion of a cap orcartridge 33 for which the bore portion 23 forms a chamber. Cap 30 is ofa form well known to the art, and is exploded by the trigger and firingpin mechanism shown most clearly in Fig. 3.

In Fig. 3 it will be noted the shell is provided with a thread 4 l,which in operation threads over thread lla on the exterior of body 2|.

Shell 40 is provided with a plug or bushin 42 in which slides firing pin43, which terminates at its upper end in a loop 44, pivotin in hole 45in the firing pin. Secured to firing pin 43 is a flange 46, againstwhich bears springs 41, whose upper end attains a purchase on the closedend 3 of shell 40, which is bored to a sliding lit for firing pin 03, asmay be seen in Fig. 3.

The trigger mechanism for firing pin 43 is provided in trigger 50,having a slot 5| engaging in a cutout 03 in the shell 40, so that thebearing portion 51a is interposed in the path of flange 06 and retainsfiring pin 33 in the raised position shown in Fig. 3, when trigger 50 isvertical as shown in Figs. 1 and 3.

Trigger 50 is provided in its upper end with an opening 53 in which asecond ring or loop 52 pivots. Fig. 4 will serve to show therelationship of this firing mechanism when in a cooked position...Engaging the loop 40 and holding the relationship between the two loopsand the cooked position of the trigger mechanism is a cord 60, having atits lower end a clip 62, as shown in Fig. 4.

Cord 60 may be a spring or the elastic cord illustrated which engagesthrough a. link 03, with a, ring 65 secured by a suitable patch 68 tothe wall of the balloon I0, opposite the appendix II.

The mechanism thus far described will show that when the balloon shellIs is inflated, cord 00 will place a tension upon the trigger mechanismand hold it cooked, and a slight consideration of the structure willshow that any deflection of shell I0s beyond a predetermined amount willrelease the tension of cord 00 and permit the pressure of spring 41 toforce flange 4'6 against the portion Ia of the trigger 50, and thattrigger, pivoting about slot 5|, will through ring 52 pull loop 44 downfar enough so that the trigger 50 will be thrown out of the path offlange 46, and firing pin 43 will be driven down by spring 41 againstcap 30, exploding the same, and discharging its flame and hot gasthrough the bore 24, and the opening 25, to detonate an explosive chargearranged thereabout, as in Fig. 1.

Loop 44 and ring 52 are preferably secured together with fine wire 65 orthe like when originally set and it will be understood that placing astrain upon cord 60 pulling up clip 62 breaks this wire. 7

The bore extension 26 of body 2i extends into and communicates withnipple 21 and serves to support the inflation valve mechanism shown indetail in Fig. 5. The inflation mechanism, Fig. 5, comprises a bushing80, which journals a stem BI, having a valve disc 83 secured thereto,and normally seated on the upper end of bushing 80 by a spring 84.

The mechanism just described follows closely well known inflationmechanisms for rubber tires, and the like. and machinery for quantityproduction is in daily operation.

To provide an optional time element in the deflation of the balloonshell, a cap 85 for nipple 21 m y be provided, cap 85 having escapevents 85, extending through its closed end and provided with an internalprojection 81, which will en age the lower end of stem 8| to an extent,and with a pressure determine on the amount that can 05 is screwed uponnipple 21. The purposes of ms deflater mechanism will be described inmore detail in connection with the operation of this device.

The following description will show that my invention contemplates acomplete departure from the former haphazard methods of releasing aerialmines and contemplates an absolute accuracy and duplication in the minesthemselves in their manufacture, in their individual operation, in theirrate of travel, in the time of their release,

d and in the time intervals between the release of individual units.

In the accomplishment of all of these objects, it is necessary that thefiring mechanism or detonator, the explosive charge, and the balloonshell-in other words, all of the parts of the mine itself, be capable ofaccurate duplication, and this is provided by the quantity manufacturingmethods already available to the parts involved.

It will be noted that all of the mechanical parts involved are such asto be readily produced by automatic machinery and that most of the partsso involved follow closely in form to those already employed inindustry. It will be understood that inflation of balloon shell 20cannot be entrusted to the former methods of manual operation ifadvantage is to be taken of the accurate duplication of parts alreadydescribed.

Fig. 6 serves to show in partial cross-section'a mechanism adapted tocontinue the absolute duplication and control essential to the bestoperation of my invention. In Fig. 6 the chuck I00 is of any of theforms and types well known to the tire inflation art wherein a valvemechanism is actuated by the insertion of a valve stem, and in this caseby the insertion of nipple 21.

To avoid complication, drawings of the internal mechanism of chuck I00have been dispensed with, but it will beunderstood that it is providedwith a gas connection IiiI to which is connected a suitable hose I02,communicating with the regulating valve I03, controlling the gas flowfrom such source as the gas cylinder I05,

Chuck I00 is preferably mounted on the body II2, sliding in thesupport'IIE and pressed upward by spring H0, whose lower end bears upona seat I14 and whose tension may be controlled by the adjusting screw II5a.

Body I15 is secured to cross-member 302 of a suitable supporting frame31H as shown in Fig. 6. Cross-member 302 also serves to support theweighing and release mechanism which comprises a lever I50, having itsend forked as indicated at I521 in Fig. 8.

Lever I50 journals upon the outer end of a suitable shaft I5I has uponits upper side a projection I50, and has therein a slot I55.

Secured to shaft I5I is a secondary lever I60, bearing upon its outerend a pin I62, which engages in slot I55 of lever I50.

Shaft I5l journals in a suitable bearing IBI and has secured to itsinner end a lever I64, whose upper end is turned inward to engage handnut I61, threading upon stem I60, whose lower end attaches to tensionspring I69, anchored at I10 to the pedestal I12 of bearing I 6I.Pedestal I12 is secured to cross-member 302 already mentioned.

In lever I60 is also mounted a stop pin I02a, which projects from itslower surface and into whose path a timing mechanism I interposes a,stop I82, as will be described.

Referring now particularly to Figs. 9, 11, 12, 13, and 14, it will beseen that the aerial mine of the form described in connection with Figs.1, 2, 3, and 4, may be conveniently delivered to the place of operationin a sealed container or box 500, provided with the internal supports50I, which bear racks 510, having guides or slides 502 and 503 joinedand separated by members 504 and 505, as specially shown in Figs. 13 and14, in such fashion that the flange 28 rides between the guide rods 502and is held thereby in regular arrangement as shown in the drawings.

Thus, the aerial mine complete may be shipped,

complete with explosives and detonator, but with the balloon shelldeflated, as shown, and is ready to be fed unit by unit into the forkI52 of the inflating mechanism, as indicated in Figs. 12 and 13, itbeing understood that when lever I50 is in position I5ta, as shown inFig. 6, the end of this fork is in registry with the guide 552, and thatonly a slight side movement of the mine units is necessary to transferfrom the shipping rack to the fork I52. Container 500 may be thus placedadjacent to the balloon discharging mechanism and the racks 55E! pickedup, each with its load of mine units, and positioned on frame 30 I, asindicated by the dotted lines 5Icd of Fig. 6. It is understood that suchracks are omitted from Fig. 6 to avoid complication, and so that thesource of inflation gas, might be shown.

It will also be seen that by this method nine units may be fed asrapidly as desired to the forks I52.

Flange 28 slides below fork I52, and appendix II projects thereabovewhen the arm I5!) is in position I5ta, as has been described. Arm I59 issupported in its raised position through the engagement of pin I62 tothe upper end of slot I55, lever I60 being held in its uppermostposition through the tension of spring IE9 operated through lever I64upon shaft I5I, as indicated in Fig. 12.

It will be noted that hand nut I N and threaded stem I68 provide meansfor regulating the tension of spring I69 and it will be seen that if thestem I63 be thrown to the right lever I55 will also be thrown to theright, and that the tension of spring I69 will now force lever I50 down,and pin I62 will engage the lower end of slot I55, as shown in Fig. 6,and force lever I58 and the mine unit carried thereby down so thatnipple 21 will engage with and open chuck I00.

The tension of spring I69 is preferably greater than that of spring no,supporting chuck Illtl, but it will be understood that both of thesesprings are of greater tension than that required to open -chuck I00,and that as these two springs force nipple 2'5 and chuck I58 togethergas flow from the cylinder H35 will begin and continue at the ratedetermined by the regulating valve I03, alread described, the gaspassing through hose I02 connection HlI to chuck Iflil, thence throughnipple 27, the valve mechanism of Fig. 5, through bore 27, and opening25 to the interior of the balloon shell I35. It will be furtherunderstood that a this gas continues to flow the balloon shell Ifis willbe inflated and that the buoyancy of the whole will increase until notonly the weight of the firing mechanism 2d and explosive Ill is borne,but the balloon commences to have a definite free lift over its totalweight.

As this proceeds, cord ell will be stretched, and in stretching willplace a tension upon clip 62, breaking safety 56, so that the solesupport for ring 52 and loop 46 becomes this same tension of cord 50,thus setting the mine and releasing its safety. The buoyancy of theballoon structure,

as it increases, places an upward tension on arm- I50, and thisincreases until the downward pressure of spring I69 is overcome andlever I6 3 is forced to the left, allowing arm I50 to rise and nipple 21releases pressure upon chuck I00 (whose amount of vertical lift iscontrolled by stop pins H6 in the support H5, as shown in Fig. 8).

After sufficient upward movement to close chuck I00 and stop the gasflow, a further movement of arm I60 will proceed until stop pin IBZaencounters latch I82 of the timing mechanism I80.

The internal mechanism of timing mechanism I will be understood tofollow a form of such devices well known to the art, and generallyincludes clock work or electrical mechanism individually controlled orconnected through suitable electrical circuits with other minemechanisms, after the fashion of those skilled in the art.

The inflation apparatus which has been described will be seen to providemeans whereby a definite quantity of inflation gas, such as hydrogen, orthe like, will be automatically introduced into each balloon unit as itis fed, and it will be seen that the tension of spring i655 willaccurately control the free lift of the inflated balloon. Thus, eachunit as it follows the preceding unit will have exactly identical freelift, and hence rate of ascension, when free in the air.

t will now be noted that timing mechanism ltd, through its stop I82,provides means to release the accurately inflated balloon unit at anexactly predetermined time, and that when stop 382 is withdrawn from thepath of stop pin I52a the tension of spring I59 will throw lever intoposition I 5% and launch the balloon unit I0 through the wind protectorand guide 360, surmounting the support frame 39!. The instant after theballoon unit is launched the rack 5H3 provides means for instantlyinserting a second unit Ill into fork H52 of lever iii-ll, if stem I58be thrown to the right; a further movement of stem M8 to the right willforce lever I58 and the new balloon unit downward so that the stem 2'!of the new unit will contact and open chuck I68, and the new fillingoperation will immediately begin, it being understood that latch I82 isreturned by the timing mechanism into the path of pin 82m after thefashion of usual operation of such mechanisms, and within the second ortwo necessary for the inflation gas to flow through chuck I69 and nipple2? into the balloon shell.

Thus, a new balloon unit will have been fully inflated, chuck it willhave again closed, and lever I55 will again return to position l5ta,before the completion of the required time interval when. timingmechanism tilt withdraws latch i82 to again release a balloon unit. Thisoperation will, of course, be repeated over the specified total time ofballoon release, as required.

Referring to Fig. 10 and to the preceding description of thisspecification, it will be understood that when a balloon unit for theknown free lift is released its rate of ascension will be substantiallyconstant, and that since this is true the altitude of each individualballoon unit at a given moment can be accurately predicted. Thehorizontal position of each balloon unit will, of course. be determinedby the prevailing winds. Under a condition of no wind at any of thelevels to which the balloon unit must pass, the ascent would, of course,be practically vertical. However, such conditions seldom, if ever,prevail.

It will be understood that Fig. 10 is for purposes of illustration only,and that in this illustration a uniform prevailing wind from lower leftto upper right is assumed. Under actual operat ing conditions, however,different wind velocities and diiferent wind directions will beencountered at various levels. This, however, will not affect thehorizontal spacing of the balloon units, since release of a trialballoon observation of its flight by theodolite, after the fashion wellknown in weather observations, will permit of determination of the lineof flight of the following balloon units, and once the horizontal pathand rate is so determined it will be understood that the necessarydimensions can be added to that of altitude so that the position of agiven balloon unit at a given instant may be accurately predicted. Thus,altitude and horizontal position being both known, the necessaryposition of the discharging units can be readily calculated, so as tointerpose the balloon unit in the path of an attacking squadron ofbombers, or the like, whose speed, altitude, and direction can be foundby the sighting devices already in use for such purposes.

The method of discharge for individual balloon. units, and thedischarger which forms a part of the method, have been described. It ispart of the purpose of this invention to duplicate such discharge in thenecessary horizontal spacing as indicated in Fig. 10, so that theindividual mines ill will be discharged in substantially parallel linesof flight, and that while such lines of flight will hardly follow theideal condition shown in 10, still, however, such lines of flight may bedistorted by the winds at various levels, the mine units will maintainnot only a vertical spacing, but also a fairly accurate horizontalspacing. It will be understood that such spacing may not necessarily beso close as to prevent the passage of an airplane between the individualshells Ill, but that if desired entanglement wire such as law may beappended to each balloon unit as it is released, and that whether or nosuch entanglement wires are attached, the multiplicity of the balloonmines, their relatively small size, and their distribution over a largearea, will form a mesh extremely difficult for a plane pilot, who mustnecessarily cut across and through the air curre its, to avoid; thatavoidance of such mines will be further complicated by their lowvisibility and by the air stream created through the plane propeller.The nightfall would, of course, further complicate the problem ofavoiding such a mine field and add a mental strain factor deterrent tobombing raids.

The ability of balloon structures to rise not only through but above thepossible altitudes for plane flight enables the mining officer to coverevery possible plane altitude from zero to their ceiling. The accuracyof spacing of the mines in the atmosphere permits the mining ofiicer toprovide channels or gaps in. the mine spacing so that his own defendingplanes may fly through the mine field.

The removal of any mine from its active or primed condition is anessential factor if the defenders civilian population and countryside isto be protected. It will be seen that this invention provides means forso removing the primed mines in that the ascension of each balloon unitabove a given predetermined altitude, depending upon the inflation ratioof the balloon shell, will cause the balloon shell to explode; suchexplosion, releasing the tension upon cord 60, will release thedetonator and explode the mine.

Th mine is similarly exploded on contact with the attacking planes ortheir propellers, and it will be seen that the balloon shell provides afairly sensitive release mechanism in that in small sizes free balloonsmay be made of extremely thin fabric since they are called upon tosustain absolutely no mechanical strain beyond that of verticallybearing the load of the explosive and detonator which form the grenade.

It will be further understood that the grenade may be of small size, andthe amount of explosive Hi small, since actual contact with any part ofthe necessarily fragile airplane shell and the explosion of a grenadethere-against will effectually remove the plane from effectiveoperation.

It will be further understood that explosive [0 may include any of theseveral thermite compositions used in incendiary bombs, together with asmall explosive charge, and that detonation will spread such incendiarycharge over an attacking plane and over its appended bombs, explodingthese while still in the air, in a fashion endangering the rest of theattacking squadron more than any object below.

Fig, 10 shows the dischargers as arranged on motor boats, but it will beunderstood that these may be equally well mounted in stationarypositions or upon vehicles of any type, that the weight of such devicesis not great, and that a single operator is sufficient for each suchdischarger.

The preferred modification of my invention which has been describedserves to illustrate a method and means of accomplishing the same: Itwill be understood, however, that known equivalents within the artsinvolved may be substituted for any of the elements herein described, asan example of which may be cited the use of parachutes adaped to orforming a part of the balloon structure itself, so that the balloon onrising to its fullest height may release the parachute device bearingthe grenade mechanism on the downward flight, or bearing simply theentanglement wires, or the like. A further equivalent for thedischarging mechanism would, of course, find embodiment in rotarydevices and like feeders employing a multiplicity of arms and chargingnozzles in simultaneous or consecutive operation.

I claim:

1. A balloon grenade, free lift controlled inflation means therefor andtime responsive looking means for said inflation means operativelyassociated therewith to release said grenade at a predetermined instant.

2. In an apparatus for providing an aerial barrage, a balloon, andinflation means for the balloon including control means for the sameoperatively associated therewith and responsive to free lift of theballoon.

3. Apparatus for providing an aerial barrage of free balloons, saidapparatus including a plurality' of balloons each carrying an explosivecharge with means to effect explosion thereof on contact of the balloonwith an aeroplane, mechanism controlled by the buoyancy of the balloonsbeing inflated acting automatically to successively inflate the balloonsto uniform buoyancy, and means operatively associated with saidmechanism for releasing the balloons therefrom in timed sequence.

4. Apparatus for providing an aerial barrage of free balloons, saidapparatus including a plurality of balloons each carrying an explosivecharge with means to effect explosion thereof on contact of the balloonwith an aeroplane, automatic mechanism for successively inflating theballoons to uniform buoyancy including a gas supply, a valve for thesupply, a free lift weighing mechanism operatively associated with saidvalve for governing the actuation of the same, and means operativelyassociated with said mechanism for releasing the balloons therefrom intimed sequence.

5. Apparatus for providing an aerial barrage of free balloons, saidapparatus including a plurality of balloons each carrying an explosivecharge with means to effect explosion thereof on contact of the balloonwith an aeroplane, automatic mechanism for successively inflating theballoons to uniform buoyancy including a gas supply, a valve for thesupply, a free lift weighing mechanism operatively associated With saidvalve for governing the actuation of the same, and automatic means forreleasing the balloons from said free lift weighing mechanism in timedsequence including timing means, a stop latch for the Weighingmechanism, and a control responsive to the timing means and associatedWith the stop latch to withdraw the same and release the Weighingmechanism.

6. In an aerial mine, in combination, a balloon unit including anenvelope and firing mechanism including a firing pin released bydestruction of the envelope, a separate explosive unit including adetonator, and assembly means for said units to ensure cooperation ofthe firing pin on one unit with the detonator on the other.

'7. In an aerial mine, in combination, an explosive container unithaving a percussion cap therein, a balloon unit comprising an envelopefor buoyant gas and a mechanism section containing a firing pin for saidpercussion cap and means to release said pin upon a reduction inpressure of said gas in said envelope; and means to connect said unitsin operative relation whereby the firing pin on one unit may strike thecap on the other.

8. In a balloon inflating and releasing device, the combination with aballoon, of inflation instrumentalities therefor controlled by thebuoyancy of the balloon, said instrumentalities including adjustingmeans for setting such control whereby an accurate preset lift of theballoon is obtained.

MYRON PENN LAUGHLIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS OTHER REFERENCES Scientific American, June 14,1913, cover page, also p. 538. (Copy may be obtained in Div. 22, Class102-33.)

